1*a325d9c4SApple OSS Distributions<h2>device_write_async</h2> 2*a325d9c4SApple OSS Distributions<hr> 3*a325d9c4SApple OSS Distributions<p> 4*a325d9c4SApple OSS Distributions<strong>System Trap</strong> - Write a sequence of bytes to a device object. 5*a325d9c4SApple OSS Distributions<h3>SYNOPSIS</h3> 6*a325d9c4SApple OSS Distributions<pre> 7*a325d9c4SApple OSS Distributions<strong>kern_return_t device_write_async</strong> 8*a325d9c4SApple OSS Distributions <strong>(mach_port_t</strong> <var>device</var>, 9*a325d9c4SApple OSS Distributions <strong>mach_port_t</strong> <var>queue</var>, 10*a325d9c4SApple OSS Distributions <strong>mach_port_t</strong> <var>request_id</var>, 11*a325d9c4SApple OSS Distributions <strong>dev_mode_t</strong> <var>mode</var>, 12*a325d9c4SApple OSS Distributions <strong>recnum_t</strong> <var>recnum</var>, 13*a325d9c4SApple OSS Distributions <strong>io_buf_ptr_t</strong> <var>data</var>, 14*a325d9c4SApple OSS Distributions <strong>io_buf_len_t</strong> <var>bytes_wanted</var><strong>);</strong> 15*a325d9c4SApple OSS Distributions</pre> 16*a325d9c4SApple OSS Distributions<h3>PARAMETERS</h3> 17*a325d9c4SApple OSS Distributions<dl> 18*a325d9c4SApple OSS Distributions<p> 19*a325d9c4SApple OSS Distributions<dt> <var>device</var> 20*a325d9c4SApple OSS Distributions<dd> 21*a325d9c4SApple OSS Distributions[in device send right] A device port to the device to be read. 22*a325d9c4SApple OSS Distributions<p> 23*a325d9c4SApple OSS Distributions<dt> <var>queue</var> 24*a325d9c4SApple OSS Distributions<dd> 25*a325d9c4SApple OSS Distributions[in io_done queue send right] The port returned from 26*a325d9c4SApple OSS Distributionsio_done_queue_create. 27*a325d9c4SApple OSS Distributions<p> 28*a325d9c4SApple OSS Distributions<dt> <var>request_id</var> 29*a325d9c4SApple OSS Distributions<dd> 30*a325d9c4SApple OSS Distributions[in send right] An unique request identifier that will be passed back as 31*a325d9c4SApple OSS Distributionspart of the io_done_result structure. 32*a325d9c4SApple OSS Distributions<p> 33*a325d9c4SApple OSS Distributions<dt> <var>mode</var> 34*a325d9c4SApple OSS Distributions<dd> 35*a325d9c4SApple OSS Distributions[in scalar] I/O mode value. Meaningful options are: 36*a325d9c4SApple OSS Distributions<p> 37*a325d9c4SApple OSS Distributions <dl> 38*a325d9c4SApple OSS Distributions<dt> <strong>D_NOWAIT</strong> 39*a325d9c4SApple OSS Distributions<dd> 40*a325d9c4SApple OSS DistributionsDo not wait if data is unavailable. 41*a325d9c4SApple OSS Distributions </dl> 42*a325d9c4SApple OSS Distributions<p> 43*a325d9c4SApple OSS Distributions<dt> <var>recnum</var> 44*a325d9c4SApple OSS Distributions<dd> 45*a325d9c4SApple OSS Distributions[in scalar] Record number to be read. 46*a325d9c4SApple OSS Distributions<p> 47*a325d9c4SApple OSS Distributions<dt> <var>data</var> 48*a325d9c4SApple OSS Distributions<dd> 49*a325d9c4SApple OSS Distributions[pointer to in array of bytes] Data bytes to be written. 50*a325d9c4SApple OSS Distributions<p> 51*a325d9c4SApple OSS Distributions<dt> <var>bytes_wanted</var> 52*a325d9c4SApple OSS Distributions<dd> 53*a325d9c4SApple OSS Distributions[in scalar] Size of data transfer. 54*a325d9c4SApple OSS Distributions</dl> 55*a325d9c4SApple OSS Distributions<h3>DESCRIPTION</h3> 56*a325d9c4SApple OSS Distributions<p> 57*a325d9c4SApple OSS DistributionsThe <strong>device_write_async</strong> function enqueues a write operation for a 58*a325d9c4SApple OSS Distributionssequence of bytes to a device object. The meaning of recnum as well as 59*a325d9c4SApple OSS Distributionsthe specific operation performed is device dependent. 60*a325d9c4SApple OSS Distributions<h3>RETURN VALUES</h3> 61*a325d9c4SApple OSS Distributions<p> 62*a325d9c4SApple OSS Distributions<strong>device_write_async</strong> returns only invalid parameter errors. 63*a325d9c4SApple OSS Distributions<h3>RELATED INFORMATION</h3> 64*a325d9c4SApple OSS Distributions<p> 65*a325d9c4SApple OSS DistributionsFunctions: 66*a325d9c4SApple OSS Distributions<a href="device_read_async_inband.html"><strong>device_read_async_inband</strong></a>, 67*a325d9c4SApple OSS Distributions<a href="DR_overwrite_async.html"><strong>device_read_overwrite_async</strong></a>, 68*a325d9c4SApple OSS Distributions<a href="device_write_async_inband.html"><strong>device_write_async_inband</strong></a>, 69*a325d9c4SApple OSS Distributions<a href="io_done_queue_create.html"><strong>io_done_queue_create</strong></a>. 70